Development of Predictive Tools for Assessment of Natural Attenuation Capacity and Treatment Transition at Chlorinated Solvent Sites
Background: Despite considerable advancements in our understanding of groundwater remediation (primarily in source zones), much less research has focused on the fate of contaminant mass associated with long-term storage and release from low permeability media, and natural attenuation (e.g., bioremediation and biologically-mediated abiotic degradation) in complex systems.
As part of long-term remedy implementation, the following must be considered: ●Reasonable timeframes to complete remediation, ●Risks associated with reliance on monitored natural attenuation (MNA) for long-term containment, ●Quantification of when diminishing returns on remedy performance could be expected, and ●Plans for managing site uncertainty and sustainability of institutional controls.
Stroo, H.F., Ward, C.H., 2010. Future directions and research needs for chlorinated solvent plumes. In In Situ Remediation of Chlorinated Solvent Plumes, Springer, New York. pgs. 699-725. doi: 10.1007/978-1-4419-1401-9_21
Overall goal: Improve fundamental understanding and prediction of sustainable natural attenuation (NA) of chlorinated solvents in complex groundwater systems over long (i.e., > 30 years) time frames, and identify conditions where it may be appropriate to transition from active to more passive treatment approaches (i.e., Monitored Natural Attenuation [MNA]) early in the life cycle of site.
Specific objectives: 1.Provide fundamental experimental data to elucidate the contributions of physical, chemical, and biological processes to the natural attenuation capacity (NAC) of chlorinated ethenes in heterogeneous aquifer formations, 2.Develop and validate multi-dimensional mathematical models simulating coupled processes governing NAC in complex hydrogeologic systems, 3.Develop and test field-scale modeling approaches that can be used to estimate and predict the NAC of aquifer formations for long-term site management, and 4.Establish benchmarks and guidance for determining when it is appropriate to transition from active treatment to passive treatment strategies.
Publications and Presentations
Pennell and Cápiro. “Biologically enhanced back diffusion in heterogeneous porous media” Microbial Insights Webinar; September 29, 2020
Investigators:
Dr. Natalie Cápiro (PI), Auburn University
Dr. Kurt Pennell (co-PI), Brown University
Dr. Mark Widdowson (co-PI), Virginia Tech
Dr. Michael Kavanaugh (co-PI), Geosyntec Consultants
Dr. Eric Suchomel (co-PI), Geosyntec Consultants